Background: Our shop installed a 2007 Vortec 5.3 with the factory motor, 4l60e trans, ecm, and wiring harness in a 2004 jeep. We kept all the newer 2007 GM emissions equipment because the customer lives in an emission checking county in Indiana. We also converted the OBDII port to communitcate with the factory GM ECM since the jeep ECM was no longer in use and all the emissions were handled by the GM computer. The first time through emissions testing when we finished the build a couple of years back went just fine because the GM ECM stated it had completed all of the needed testing and all passed.
The Problem: The jeep went back to get tested again this year for new plates and will not pass inspection. The issue is not with the emissions equipment. It comes back with all internal checks good. The issue is that the state is now scanning the VIN number in the ECM to verifiy it matches vehicle. Naturally the GM ECM VIN number comes up as a 2007 GM truck since that is where the drivetrain came from. My understanding is that I just can't change out the VIN code to something that is not a GM based VIN code.
I tried searching the forms, but was not able to locate a thread that helped me out. If I missed one I apologize up front.
Thanks,